ObjectiveTo observe the changes in open probability and protein expression of large conductance Ca2+-activated K+ (BK) channel in retinal vascular smooth muscle cells (RVSMCs) of diabetic rats. MethodsStreptozotocin (STZ)-induced rat diabetic animal model was established by STZ injection intraperitoneally.RVSMCs were isolated by enzyme digestion. The BK currents in control and diabetic groups were recorded by patch clamp technique in single channel configuration. BK channel protein expression in control and diabetic group were measured by Western blot. ResultsCompared with control group, the NP0 of BK channels in diabetic group were significantly increased (t=4.260, P < 0.05). Compared with control group, there was no significant difference inα-subunit protein expression in diabetic group in RVSMCs (t=10.126, P > 0.05); however, β1-subunit protein expression was remarkably increased in diabetic group (t=5.146, P < 0.05). ConclusionThe NP0 of BK channels andβ1-subunit protein expression are increased in RVSMCs of diabetic rats.
Diabetic retinopathy is a serious complication of diabetes and is the leading cause of blindness in people with diabetes. At present, there are many views on the pathogenesis of diabetic retinopathy, including the changes of retinal microenvironment caused by high glucose, the formation of advanced glycation end products, oxidative stress injury, inflammatory reaction and angiogenesis factor. These mechanisms produce a common pathway that leads to retinal degeneration and microvascular injury in the retina. In recent years, cell regeneration therapy plays an increasingly important role in the process of repairing diseases. Different types of stem cells have neurological and vascular protection for the retina, but the focus of the target is different. It has been reported that stem cells can regulate the retinal microenvironment and protect the retinal nerve cells by paracrine production, and can also reduce immune damage through potential immunoregulation, and can also differentiate into damaged cells by regenerative function. Combined with the above characteristics, stem cells show the potential for the repair of diabetic retinopathy, this stem cell-based regenerative therapy for clinical application provides a pre-based evident. However, in the process of stem cell transplantation, homogeneity of stem cells, cell delivery, effective homing and transplantation to damaged tissue is still a problem of cell therapy.
ObjectiveTo assess the association of vascular endothelial growth factor (VEGF) gene-460C/T and-634C/G polymorphism with diabetic retinopathy (DR) among patients in Asia and European by meta-analysis. MethodsA systematic search of electronic databases (PubMed, Cochrane Library, EMBASE, VIP, Wanfang technological, CNKI, etc.) was carried out until Jun, 2014. Case-control studies on the relationship between genetic polymorphism of VEGF-460C/T and VEGF-634C/G with diabetic retinopathy were included in this analysis. The data were quantitatively analyzed by RevMan 5.0 software after assessing the quality of included studies. The pooled odds ratios (OR) and their corresponding 95% confidence intervals (CI) were used to assess the strength of the association. ResultsVEGF-460C/T (7 studies:899 cases and 786 controls) and VEGF-634C/G (10 studies:1615 cases and 1861 controls) were inclued in this meta-analysis. Significant association was found for-460C/T polymorphism in Aisa (C versus T:OR=1.52, 95%CI was, Z=3.72, P=0.0002; CC versus CT+TT:OR=1.61, 95%CI was[1.22, 1.90], Z=3.05, P=0.002; TT versus CT+CC:OR=0.64, 95%CI was[1.19, 2.19], Z=2.07, P=0.04), and VEGF-634CC gene type was associated with DR in European (OR=1.56, 95%CI[1.08, 2.25], Z=2.37, P=0.02). No significant publication bias was found. ConclusionsThe meta-analysis demonstrated that DR was associated with VEGF-460C/T polymorphism in Asia, and C alleles and CC gene type was the risk polymorphism; VEGF-634C/G polymorphism was not associated with DR, but its CC genotype maybe the risk factor in European. Further case-control studies based on larger sample size are still needed, especially for-634C/G polymorphism.
Objective To analyze the expression of apoptosis-related genes of retinal blood vessel in early diabetic rats by gene chip technology. Methods To make diabetic rat model by intraperitoneal injection of streptozotocin (STZ). On the 6th week after blood pressure increased, 10 rats were executed in Diabetic group and normal control group respectively. 20 retinal blood vessels were extracted and the RNA was isolated. The probe was made of alpha;-32 P-deoxyadenosine triphosphate (dATP)-labeled sample which hybridized 1176 nylon chips, and then analyzed by software. Three different expression genes were selected to verify by reverse transcription polymerase chain reaction (RT-PCR). Results On the 6th week, 136 （11.5％） genes were differentially expressed ［up-regulated genes were 90(7.6%), down-regulated genes were 46(3.9%)］in diabetic group. These genes involved into different groups according to their function. Especially in 72 apoptosis-related genes, 15 genes were differentially expressed. The up-regulated genes were some TNF receptor family members such as TNFRSF12, TRAIL, TNFRSF9, FADD；Bcl-2 family members such as bcl-w, bax, bak1 and AKT. The down-regulated genes were FAF1 which related to fas. Conclusions The expression of retinal vascular gene in early diabetic rats has been changed complicatedly. In particular, the multiple apoptosis-related genes have been changed in early diabetic, and most of them are at the upstream of apoptosis pathway. These findings indicate that the development of diabetic retinopathy is associated with multiple signaling pathways leading to apoptosis, while the alterations on the level of molecular biochemistry are still limited in apoptosis induction period. （Chin J Ocul Fundus Dis，2008，24：244-248）
ObjectiveTo observe the serum vascular endothelial growth factor (VEGF), apelin and heme oxygenase-1 (HO-1) levels in patients with type 2 diabetes mellitus (T2DM) and to explore their their relationship with diabetic retinopathy (DR).MethodsA total of 208 patients with T2DM and 50 healthy subjects (control group) from the Central Hospital of Western Hainan during January 2014 and December 2017 were selected in this study. Vision, slit lamp microscope, indirect ophthalmoscope and FFA examinations were performed on all the subjects. According to the results of the examinations combined with the DR clinical staging criteria, the patients were divided into non-DR (NDR) group, non-proliferative DR (NPDR) group, and proliferative DR (PDR) group, with 72, 76 and 60 patients in each, respectively. The clinical data of each group were recorded, and the levels of fasting blood glucose (FPG), HbA1c, total cholesterol (TC), three acylglycerol (TG), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), VEGF, apelin and HO-1 were detected in each group. The receiver operating characteristic curve (ROC) were used to analyze the value of VEGF, apelin and HO-1 in predicting the occurrence of PDR. Correlation analysis of serum VEGF, Apelin and HO-1 with clinical parameters in PDR patients by Pearson correlation analysis.ResultsThe level of VEGF (56.82±10.16 vs 91.74±22.83, 140.15±36.40, 195.28±42.26 pg/ml) and apelin (2.95±0.53 vs 4.68±0.74, 7.25±1.13, 10.16±1.35 ng/ml) in PDR group were significantly higher than those in NPDR, NDR and control groups (F=17.306, 21.814; P＜0.05). The level of HO-1 (50.37±10.14 vs 43.58±8.16, 30.25±6.28, 22.60±4.72 mmol/L) in PDR group was significantly lower than those in NPDR, NDR and control groups (F=15.827, P＜0.05). The ROC curve analysis showed that the best cut-off values of serum VEGF, apelin and HO-1 were 162.50 pg/ml, 8.30 ng/ml, 27.13 mmol/L, and the three combined to predict PDR of AUC (95%CI) was 0.906 (0.849?0.962), and their sensitivity (90.3%) and specificity (83%) were better. The correlation analysis showed that the VEGF, apelin and HO-1 of PDR patients were correlated with the course of diabetes (r=0.382, 0.416, ?0.36; P＜0.05), FPG (r=0.438, 0.460, ?0.397; P＜0.05) and HbAlc (r=0.375, 0.478, ?0.405; P＜0.05), and the serum VEGF were correlated with apelin and HO-1 (r=0.793, ?0.594; P＜0.01).ConclusionElevated serum VEGF and apelin levels and reduced HO-1 levels are associated with the progression of DR, and the three combination helps predict the occurrence of PDR.
Objective To observe the serum betatrophin levels in patients with type 2 diabetes mellitus (T2DM) and to explore the role of betatrophin in the pathogenesis of diabetic retinopathy (DR). Methods A total of 59 patients with T2DM (DM group) and 14 healthy controls (NC group) were enrolled in the study. Vision, slit lamp microscope, indirect ophthalmoscope, fluorescein fundus angiography were performed on all the subjects. According to the results of the examination combined with the international DR clinical staging criteria, the patients were divided into no DR (Non-DR) group, non-proliferative DR (NPDR) group, and proliferative DR (PDR) group, with 30, 20 and 9 patients in each, respectively. The fasting blood glucose (FPG), insulin (FIN), C-peptide, glycated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C), low-density lipid Protein (LDL-C) levels were detected. The level of betatrophin in serum was determined by enzyme-linked immunosorbent assay. The correlation between betatrophin and other indicators was analyzed by Spearman correlation. The influencing factors of PDR were analyzed by logistic regression. Results Compared with subjects in the NC group, the level of FPG (F=-4.316, P＜0.001), FIN (F=2.142, P=0.001), HbA1c (F=-5.726, P＜0.001), TC (t=3.609, P=0.010), LDL-C (t=0.000, P=0.003), and betatrophin (F=-2.263, P=0.024) were significantly increased and HDL-C level (F=-3.924, P＜0.001) was decreases in the DM group. The difference of TG level between two groups was not statistically significant (F= -1.422, P=0.155). Compared with the Non-DR group and the NPDR group, the serum C-peptide (F=7.818, P=0.020) and betatrophin levels (F=12.141, P=0.002) were significantly increased in the PDR group. Spearman correlation analysis showed that the levels of betatrophin in the DM group was positively correlated to TC (r=0.304, P=0.019). The serum levels of betatrophin was positively correlated to body mass index in the Non-DR group (r=0.513, P=0.004). Furthermore, in the PDR group, a significant positive correlation was observed between the serum betatrophin levels and diastolic blood pressure (r=0.685, P=0.042). Logistic regression analysis showed that the duration of diabetes, serum C-peptide and betatrophin levels were risk factors for PDR. After controlling for the duration and serum C-peptide, the PDR risk for betatrophin levels great than or equal to 1.0 ng/ml was 12 times as much as betatrophin levels less than 1.0 ng/ml in T2DM patients. Conclusions The serum betatrophin content of patients with T2DM is abnormal. Betatrophin may be involved in the occurrence and development of PDR.
The exact pathophysiological mechanisms of diabetic retinopathy (DR) remain elusive. The inflammatory reaction, retinal vascular leakage and retinal neovascularization are main features of DR. Adiponectin (APN) is an endogenous biological active protein secreted by adipocytes. It can increase insulin sensitivity, regulate blood glucose and lipid metabolism, and has anti-inflammation and anti-neovascularization functions. It may be involved in the development of DR. This review summarized the studies on the association between APN and DR in recent years.
Objective To determine the association of -429T/C and G1704T polymorphisms in the receptor for advanced glycation end products gene with proliferative diabetic retinopathy (PDR). Methods Case-control study. From the Beijing Desheng Diabetic Eye Study cohort of 1467 patients with type 2 diabetes mellitus (T2DM),atotal of 97 patients with PDR and 105 diabetic patients without retinopathy (DWR, duration of diabetes 15 years) were included for this study. Questionnaires were collected and general ophthalmologic examinations were performed. Biochemical analysis was conducted. DNA was extracted from peripheral venous blood. The -429T/C and G1704T single nucleotide polymorphisms were detected by the means of PCR-restrication fragment length polymorphisms. Results The frequency distribution of -429T/C in DWR group was 81.0% in TT, 16.1% in TC, 2.9% in CC. The frequency distribution of -429T/C in PDR group was 77.3% in TT, 20.6% in TC, 2.1% in CC. There was no significant statistical difference between the two groups (χ2=0.40, P > 0.05). Frequency of the -429T/C minor alleleCin the DWR and PDR group were 11.0% and 12.4%, respectively, with no significant statistical difference between the two groups (χ2=0.20，P > 0.05). The frequency distribution of G1704T in DWR group was 66.7% in GG, 29.5% in GT, 3.8% in TT. The frequency distribution of G1704T in PDR group was 78.4% in GG, 21.6% in GT. There was no significant statistical difference between the two groups (χ2=3.44, P > 0.05). Frequency of the G1704T minor alleleTin the DWR and PDR group were 18.6% and 10.8%, respectively, in which significant difference was found within the two groups (χ2=4.79, OR=1.88，95%CI: 1.06 - 3.33, P > 0.05). Conclusions G1704T polymorphism is associated with PDR presence and 1704G allele may increase the risk of PDR.
O-linked N-acetylglucosamine (O-GlcNAc) glycosylation is an important form of post-translational protein modification, mainly intracellular. It is closely related to cellular signaling pathways, and is involved in signal transduction, gene transcription and other important biological processes. Studies have found that O-GlcNAc glycosylation is directly related with diabetic retinopathy (DR), further studies may help us to uncover the DR mechanism, and develop new strategies for the diagnosis and treatment of this disease.
Objective To observe the correlation between postmenopausal estrogen levels and diabetic retinopathy (DR) in women. Methods Thirty-nine menopause female patients with type 2 diabetes mellitus and 17 menopause subjects (control group) were enrolled in this study. Control subjects aged from 53 to 82 years, with the mean age of (69.80±8.32) years. Diabetes mellitus patients aged from 56 to 84 years, with the mean age of (70.50±8.27) years; diabetes duration ranged from 3 to 23 years, with the average course of diabetes (11.40±7.97) years. DR diagnosis was according to the results of fundus fluorescein angiography, and thus the 39 patients were divided into DR group (19 patients) and non-DR (NDR) group (20 patients). There was no significant difference in age and menopause duration between the three groups (t=0.347, 0.485;P＞0.05). There was significant difference in diabetes course (t=2.748,P＜0.05). Compared with NDR group, fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) were significantly increased (t=6.130, 5.322, 4.574, 2.426, 4.033), high density lipoprotein cholesterol (HDL-C) was significantly lower (t=3.917), the difference was statistically significant (P＜0.05). The level of estradiol (E2) was measured by radioimmunoassay. The differences of E2 levels between the three groups were compared. Logistic regression analysis was used to analyze the influencing factors of DR. Results The levels of E2 in control group, DR group and NDR group were (42.38±8.64), (21.49±9.81) and (32.72±10.51) pg/ml, respectively. The level of E2 in DR group was significantly lower than that in NDR group and control group (t=3.443, 10.110;P＜0.05). Logistic regression analysis showed that the duration of diabetes mellitus [coefficients =0.166, odds ratio (OR)=1.181,P= 0.016], FBG (coefficients=1.162,OR=4.014,P=0.001), TC (coefficients=3.212,OR=10.820,P=0.002), TG (coefficients=1.649,OR=5.203,P= 0.030) and LDL-C (coefficients=1.605,OR= 4.976,P=0.003) were the risk factors for DR; E2 (coefficients=?0.100,OR=0.904,P=0.004) and HDL-C (coefficients=?4.460,OR=0.012,P=0.002) were the protective factors for DR. Conclusion The estrogen level of postmenopausal women have a certain correlation with the development of DR, it may be one of the protective factor of DR.